Part 2 of the Radio 4 series, "The Matrix of Power", examines what could be the most radical of the government's constitutional reforms: the transfer of powers from Westminster to new, devolved legislatures in Edinburgh, Belfast and Cardiff.

The main argument for devolution was that it would bring power closer to the people and head off Scottish demands for full independence.

Labour's commitment to this pre-dates Tony Blair's leadership and goes back to the days when Labour was the dominant party in Scotland, but looked like remaining permanently in opposition at Westminster.

The prospect of an autonomous Scottish Parliament at Edinburgh may now look far less attractive to Mr Blair's centralising team at Downing Street, especially if the Scottish Nationalist Party leads the polls when elections are held next year.

Regardless of which party wins those elections, Scotland's first devolved government is bound to want a say on European Union issues like fisheries and the Common Agricultural Policy, and on foreign policy generally.

There are also bound to be rows with the centre about money, since Scotland will continue to depend for most of its revenues on a block grant from Westminster.

So the new parliament, far from satisfying Scottish aspirations, could well become the platform for a continuing campaign for independence.

The other major flaw in the present devolution scheme is the very wide disparity between the autonomy that is being devolved to Scotland compared to the rest of the United Kingdom: Wales and Northern Ireland are getting far fewer powers, while the English regions are getting none.

There's obvious potential here for a backlash from deprived areas of England like the north-east and north-west, which might feel the Scots are having their cake and eating it. Consequently, the government's plans risk satisfying no one, while fuelling tensions that might ultimately weaken the Union.

Since the United Kingdom is no longer sustainable as a unitary state, perhaps the most realistic and sensible option might be to replace it with a balanced, coherent and clearly defined federation, in which all the constituent units, including the English regions, have equal autonomy and powers.

But that would require a drastic reform of Westminster itself to turn it into a federal parliament. And it would also require the Blair government to loosen the reins of central control and share real power with the regions.

Some constitutional experts believe that the process is already unstoppable and that the momentum of devolution will inevitably grow into full federalism, whether or not politicians use the F-word.